The present invention relates to an extrusion head device which is coupled to rubber- or resin-extruding machines. More specifically, the present invention relates to an extrusion head device in which fixed head parts and movable head parts as a plurality of separate parts can be easily combined using compact fastening means.
In extrusion heads which are coupled to rubber- or resin-extruding machines, each passage for extruded material is often separated along the longitudinal direction into upper and lower portions provided in a plurality of head parts. Such an openable and closable structure of an extrusion head having a plurality of head parts separated makes it easy to remove extruded material remaining in the passages and to perform cleaning and maintenance. In this separate-type extrusion head, at the time of extrusion, the separate head parts must be reliably combined so that extruded material does not leak from the mating surface.
Fastening means provided in such a separate-type extrusion head has been proposed in, for example, Japanese Patent Publication No. 2609261. In this proposal, a separate-type head unit includes a fixed head part and a movable head part, and is provided with hammer-shaped tip portions which can be expanded from the fixed head part side by cylinder rods. These hammer-shaped tip portions pass through recessed portions which are shaped like through holes and provided on the movable head part side, then rotate about the rod axes by 90 degrees, and are hung on the top end surfaces of the recessed portions. Thereafter, the cylinder rods move in the contracting direction, whereby the movable head part is pressed against the fixed head part by the hammer-shaped tip portions to be fastened thereto.
However, this proposal requires rotation mechanisms for rotating the cylinder rods about the axes thereof, in addition to mechanisms for moving the cylinder rods forward and backward. Accordingly, there is the problem that the structure becomes complicated.
Further, when the movable head part is fastened to the fixed head part, large compressive stress acts on contact portions between the hammer-shaped tip portions and the end surfaces of the recessed portions. Accordingly, in the case where the hammer-shaped tip portions are small, there is the problem that the contact portions are prone to deformation. If the hammer-shaped tip portions are widened in order to reduce the deformation, there is a need of sufficient spaces to allow the hammer-shaped tip portions to operate without interfering with other portions. Accordingly, there is the problem that the entire head becomes considerably large.